单元尺寸自密实混凝土抗压强度Weibull分布研究

Study on The Weibull Distribution of Compressive Strength of Self-compacting Concrete in Unit Size

为了研究骨料组成对自密实混凝土抗压强度Weibull分布的影响,对自密实混凝土的砂子和碎石进行粒径筛选,并通过人工控制材料的均匀程度,浇筑了大量具有不同粒径特征的试件。根据500个试件的单轴抗压强度数据,利用数理统计方法得出Weibull分布中的均质度系数,随后将该系数赋值到数值软件中进行建模分析。通过物理试验发现:随着粒径增加,抗压强度呈先降低后上升的趋势;均质度系数的取值范围为4.67~7.99。数值模拟结果显示:均质度系数越小,损伤单元数量越多,模型产生较多裂缝,破坏较为碎片化;随着均质度增大,损伤单元变少,应力集中现象减弱,局部损伤和裂缝减少。

In order to study the influence of aggregate composition on the distribution of Weibull compressive strength of self-compacting concrete,the particle size of sand and gravel of self-compacting concrete was screened,and a large number of specimens with different particle size characteristics were poured by manually controlling the uniformity of the materials.According to the uniaxial compressive strength data of 500 specimens,the homogeneity coefficient in the Weibull distribution was obtained by mathematical statistical method,and then the coefficient was assigned to the numerical software for modeling and analysis.Through physical experiments,it is found that with the increase of particle size,the compressive strength decreases first and then increases.The value range of the homogeneity coefficient is 4.67~7.99.The numerical simulation results show that the smaller the homogeneity coefficient and the greater the number of damage elements,the more cracks and fragments of the model will be.With the increase of homogeneity,the damage elements decreased,the stress concentration phenomenon decreased,and the local damage and cracks decreased.